The degradation characteristics of the new mixed strains isolated from a de-sizing process which could degrade PVA thoroughly were studied. The interrelation of seven kinds of single bacterium separated from mixed strains was studied through combination experiments. The degradation process was analysed through UV spectrum, IR, GPC and other methods. The enzymatic properties and enzymatic reaction dynamic processes were studied. The results showed that PVA with the initial average molecular weight of 51,260 Da could be degraded thoroughly by seven kinds of single bacterium because of their mutual coordination effect. In addition, some carboxylic acid and methyl ketone substances could be produced in the PVA degradation process by some bacteria (mainly A4 and C1). These middle smaller molecular weight materials would be further degraded thoroughly by other bacteria (mainly A1 and A3). The PVA-degrading enzyme that was produced by the mixed strains was mainly an exocellular enzyme. The enzyme reaction kinetics equation was v = 19.5[S]/(2.06 × 10(-3) + [S]).